Washington University School of Medicine and the affiliated Barnes-Jewish Hospital have a long tradition of excellence in musculoskeletal research, patient care, education and training. During the past 40 years, a broad program in bone biology consisting of members of the Division of Bone and Mineral Diseases and associated investigators from other Divisions and Departments have provided the institutional and human resources in support of investigators and clinicians committed to diseases of mineral metabolism and skeletal disorders. A Mineral and Skeletal Metabolism Training Grant, AR007033, was continuously funded for more than 3 decades, and until 2004, was fundamental to accomplishing our teaching mission. In this new proposal, we seek to re-establish an interdisciplinary, institutional Metabolic Skeletal Disorders Training Program (MSDTP) to mentor and train the next generation of scientists and clinician-scientists in skeletal research, building upon the depth of talent at our institution. This program will offer pre- and post-doctoral training in 5 thematic areas: 1) Biology of the osteogenic lineage; 2) Osteoclast biology and inflammatory skeletal disorders; 3) Metastatic bone disease; 4) Skeletal development and repair; 5) Genetics of skeletal disorders. These themes represent the focus of the faculty participating in this training program and reflect common interests and interactions within each research group. The pool of Preceptors selected for this MSDTP are drawn from 5 academic Departments at Washington University (Internal Medicine, Orthopaedic Surgery, Pathology and Immunology, Developmental Biology, and Anatomy and Neurobiology) and reflects broad research interests, including skeletal development, osteoblast, osteoclast and chondrocyte biology, cell signaling, stem cell and structural biology, bone-immune and hematopoietic system interactions, biomechanics, ectopic calcification, as well as mouse and human genetics, bone metastasis and inflammatory osteolysis. The training will consist of 4 components: 1) mentored research training; 2) core curriculum coursework; 3) career development coursework; 4) presentation and reporting skills. The post-doctoral training program will offer either a basic science- or a translational/clinical- oriented pathway. The pre-doctoral training pathway will be integrated with the PhD and MD/PhD programs administered by the Division of Biology and Biomedical Sciences (DBBS), which manages the graduate programs at Washington University. A streamlined but focused administrative structure will manage trainee recruitment, appointment and progress and monitor the program success. The program, which builds on strong interdepartmental and School-wide support, will leverage on existing institutional infrastructure, such as the Division of Bone and Mineral Diseases (for resources and facilities), the DBBS (for trainee recruitment and coursework), and the Institute for Translational and Clinical Sciences (for cores, services and formal training). Training the next generation of physicians and scientists is paramount to the continuous growth of research on skeletal biology. Such research is necessary to understand the genetic and molecular bases of skeletal disorders, and to devise new treatment strategies for diseases such as osteoporosis, inflammatory osteolysis, osteoarthritis, tendon failure, and bone metastasis, which afflict a large proportion of the elderly population.